研究：氣候變化將使北極熊在本世紀末滅絕

近幾年我們經常從新聞上看到餓得皮包骨頭的北極熊，因爲氣候變暖、海冰消融，靠浮冰捕食海豹爲生的北極熊長期找不到食物，甚至淪落到去垃圾堆裏翻找東西吃。然而更可悲的是，如今科學家的新研究發現，北極熊很可能撐不過這個世紀了。

Climate change is starving polar bears into extinction, according to research published Monday that predicts the apex carnivores could all but disappear within the span of a human lifetime. In some regions they are already caught in a vicious downward spiral, with shrinking sea ice cutting short the time bears have for hunting seals, scientists reported in Nature Climate Change.

週一發佈的一項研究稱，氣候變化正在餓死北極熊並迫使它們滅絕。該研究預測，北極熊這一食物鏈頂端的食肉動物可能會在百年內幾近滅絕。科學家在《自然氣候變化》上發表的報告稱，在部分地區，由於海冰消融縮短了北極熊捕食海豹的時間，北極熊已經陷入數量螺旋式下降的惡性循環。

all but: 幾乎，差一點

Their dwindling body weight undermines their chances of surviving Arctic winters without food, the scientists added.

科學家補充道，因爲體重不斷下降，北極熊在沒有食物的情況下熬過北極冬天的機率降低了。

"The bears face an ever longer fasting period before the ice refreezes and they can head back out to feed," Steven Amstrup, who conceived the study and is chief scientist of Polar Bears International, told AFP.

該研究的提出者、北極熊國際協會的首席科學家斯蒂芬·阿姆斯特拉普告訴法新社說：“在冰雪重新凍結、可以外出覓食前，北極熊面臨着前所未有的超長禁食期。”

On current trends, the study concluded, polar bears in 12 of 13 subpopulations analyzed will have been decimated within 80 years by the galloping pace of change in the Arctic, which is warming three times as fast as the planet as a whole.

該研究得出結論稱，按照目前的趨勢，隨着北極加速變暖，研究分析的13個北極熊亞種羣將有12個在80年內滅絕。目前北極變暖速度是地球整體的三倍。

"By 2100, recruitment" — new births — "will be severely compromised or impossible everywhere except perhaps in the Queen Elizabeth Island subpopulation," in Canada's Arctic Archipelago, said Amstrup.

阿姆斯特拉普稱，“到2100年，新生北極熊數量將會劇減甚至降爲零，除了（加拿大北極羣島的）伊麗莎白女王羣島的亞種羣之外”。

That scenario foresees Earth's average surface temperature rising 3.3 degrees Celsius above the preindustrial benchmark. One degree of warming so far has triggered a crescendo of heatwaves, droughts and superstorms made more destructive by rising seas.

科學家預測，到那時地球的平均表面溫度將比工業化前基準水平高出3.3攝氏度。變暖1度迄今爲止已經引發日益嚴重的熱浪、乾旱和超級風暴，而海平面上升使得風暴更具破壞力。

crescendo [krəˈʃendoʊ]: n. 漸強；頂點

But even if humanity were able to cap global warming at 2.4 degrees Celsius — about half-a-degree above Paris Agreement targets, but hugely ambitious all the same — it would probably only delay the polar bears' collapse.

但即使人類可以將全球變暖控制在2.4攝氏度以內——比巴黎協定目標大約高出0.5度，但也是極爲雄心勃勃的計劃——這也很可能只會將北極熊滅絕的時間往後推遲一點。

The threat is not rising temperatures per se but the top-of-the-food-chain predators' inability to adapt to a rapidly shifting environment.

威脅不是來自氣溫升高本身，而是源自北極熊無法適應快速變化的環境。

per se [,pə:'sei]: 本身，自身

Half of Earth's land-based megafauna are classified as threatened with extinction, but only polar bears are endangered primarily by climate change.

地球上有一半的陸地巨型動物被歸類爲瀕危物種，但只有北極熊主要是因爲氣候變化而瀕臨滅絕。

megafauna: 巨型動物

But that status may not be unique for long, and should be seen as a harbinger of how climate will impact other animals in the coming decades, the authors warned.

研究報告的作者們警告稱，但是北極熊也許不會長期獨自處於這種境地，而應被視爲預示着未來數十年氣候將如何影響其他動物的一個先驅者。

harbinger [ˈhɑːrbɪndʒər]: n. 先驅；前兆；預告者

The polar bear's "vulnerable" status on the IUCN Red List of endangered species — less severe than "endangered" or "critically endangered" — does not accurately reflect their plight, the authors argue.

北極熊在國際自然保護聯盟的瀕危物種紅色名單上屬於“脆弱”等級——沒有“瀕危”或“極危”那麼嚴重，研究作者指出，這一等級沒有準確反映出它們的困境。

Categories established by the International Union for the Conservation of Nature are based mainly on threats such as poaching and habitat encroachment that can be addressed with local action on the ground.

國際自然保護聯盟設立的等級主要基於偷獵和棲息地破壞等威脅，這些都可以通過當地行動來解決。

"But we cannot build a fence to protect sea ice from rising temperatures," said Amstrup.

阿姆斯特拉普說：“但我們無法建起圍欄來保護海冰不受氣溫升高的影響。”